Physics Practice Questions - Light

D

1) Most of the waves in the electromagnetic spectrum are A) red light. B) blue light. C) green light. D) invisible. E) visible F) Light Waves

D

11) If an electron vibrates up and down 1000 times each second, it generates an electromagnetic wave having a A) period of 1000 s. B) speed of 1000 m/s. C) wavelength of 1000 m. D) frequency of 1000 Hz. E) wavelength of 1000 km.

D

12) The source of all electromagnetic waves is A) heat. B) magnetic fields. C) electric fields. D) vibrating charges. E) none of these

A

13) Which of the following is fundamentally different from the others? A) sound waves B) X-rays C) gamma rays D) light waves E) radio waves

A

14) The natural frequency of the atoms in glass is in the A) infrared part of the spectrum. B) visible part of the spectrum. C) ultraviolet part of the spectrum.

B

15) When ultraviolet light is incident upon glass, atoms in the glass A) are forced into vibration. B) resonate. C) pass the light energy along practically undiminished. D) freely absorb and re-emit most of the ultraviolet light.

A

16) When visible light is incident upon clear glass, atoms in the glass A) are forced into vibration. B) resonate. C) convert the light energy into internal energy.

C

17) Consider light energy that is momentarily absorbed in glass and then re-emitted. Compared to the absorbed light, the frequency of the re-emitted light is A) considerably less. B) slightly less. C) the same. D) slightly more. E) considerably more.

B

18) The speed of light in the void between molecules in glass is A) more than its speed in a vacuum. B) the same as its speed in a vacuum. C) less than its speed in a vacuum. D) I don't know E) none of the above

B

19) Compared to its average speed in air, the average speed of a beam of light in glass is A) more. B) less. C) the same.

B

2) Electromagnetic waves consist of A) compressions and rarefactions of electromagnetic pulses. B) oscillating electric and magnetic fields. C) particles of light energy. D) high-frequency gravitational waves.

C

20) Infrared waves are often called heat waves because they A) emanate from relatively hot sources. B) consist of frequencies lower than those of visible light. C) induce resonance in molecules and increase internal energy in a substance. D) are absorbed rather than reflected by the skin. E) are the predominant waves emitted by the sun.

A

21) Materials generally become warmer when light is A) absorbed by them. B) reflected by them. C) transmitted by them. D) all of these E) none of these

A

22) Sunburns are produced by A) ultraviolet light. B) visible light. C) infrared light. D) all of these E) none of these

B

23) The Earth's atmosphere is transparent to most waves in the A) infrared part of the spectrum. B) visible part of the spectrum. C) ultraviolet part of the spectrum. D) entire electromagnetic spectrum.

C

25) A solar eclipse occurs when the A) sun passes into Earth's shadow. B) moon passes into the Earth's shadow. C) the moon's shadow touches Earth.

B

26) A partial solar eclipse occurs for people in the sun's A) umbra. B) penumbra. C) none of these

D

27) While Earth is experiencing a total solar eclipse an observer on the side of the moon facing the earth would see A) Earth disappear from the sky. B) Earth dim and turn reddish. C) nothing unusual. D) a tiny dark spot move across the face of Earth.

C

35) If a light signal and a radio signal were emitted simultaneously from Alpha Centauri, the first to reach Earth would be the A) radio signal. B) light signal. C) both would reach Earth at the same time.

B

36) Which of the following cannot travel in a vacuum? A) a light wave B) a sound wave C) a radio wave D) All can travel in a vacuum. E) None can travel in a vacuum.

E

37) The main difference between a radio wave and a sound wave is their different A) frequencies. B) wavelengths. C) energies. D) amplitudes. E) modes of travel.

C

38) If the sun were to disappear right now, we wouldn't know about it for 8 minutes because it takes 8 minutes A) for the sun to disappear. B) to operate receiving equipment in the dark. C) for light to travel from the sun to the Earth. D) all of these E) none of these

B

39) Glass is transparent to wave frequencies that A) match its natural frequencies. B) are below its natural frequencies. C) both of these D) none of these

C

4) A source of electromagnetic waves is A) Stationary charged particles . B) vibrating atoms. C) accelerating electric charges. D) crystalline fluctuations. E) none of these

A

40) Glass is opaque to wave frequencies that A) match its natural frequencies. B) are below its natural frequencies. C) both of these D) none of these

A

41) A pair of sunglasses and a pair of clear reading glasses are left in the sunlight. The hotter glasses would be the A) sunglasses. B) reading glasses. C) both D) neither

B

42) The moon would be at its fullest just before the time of a A) solar eclipse. B) lunar eclipse. C) both of these D) none of these

C

43) What is the wavelength of an electromagnetic wave that has a frequency of 1 hertz? A) less than 1 m B) 1 m C) more than 1 m

C

44) What is the wavelength of an electromagnetic wave that has a frequency of 3 kilohertz? A) less than 1 km B) 1 km C) more than 1 km

B

45) What is the frequency of an electromagnetic wave that has a wavelength of 300,000 km? A) less than 1 Hz B) 1 Hz C) more than 1 Hz

A

48) At the same time an astronaut on the moon sees a solar eclipse, observers on Earth see A) a lunar eclipse. B) a solar eclipse. C) no eclipse at all.

A

49. Polarization is a property of A) transverse waves. B) longitudinal waves. C) both D) neither

C

5) Electromagnetic waves can travel A) through a vacuum. B) through a medium. C) through either a medium or a vacuum.

A

50) The vibrational direction of the electron and the plane of polarization of the light it emits A) are the same. B) are at right angles to each other. C) may or may not be at right angles to each other. D) are independent of each other.

B

51) Some double-pane airplane windows darken when the inner pane is rotated. The panes are A) thin films. B) Polaroid filters. C) optical fibers.

B

52) Light will not pass through a pair of Polaroids when their axes are A) parallel. B) perpendicular. C) 45 degrees to each other. D) two of these E) all of these

A

53) The glare seen from water is largely A) horizontally polarized. B) vertically polarized. C) non polarized.

A

54) The polarization axes of ordinary sunglasses are A) vertical. B) horizontal. C) at right angles to each other.

C

55) The polarization axes of glasses for 3-D viewing are A) vertical. B) horizontal. C) at right angles to each other.

E

6) The main difference between a radio wave and a light wave is its A) speed. B) wavelength. C) frequency. D) all of these E) two of these

C

7) Which of these electromagnetic waves has the shortest wavelength? A) radio waves B) infrared waves C) X-rays D) ultraviolet waves E) light waves

B

8) Compared to ultraviolet waves, the wavelength of infrared waves is A) shorter. B) longer. C) the same.

C

9) Compared to radio waves, the velocity of visible light waves in a vacuum is A) less. B) more. C) the same.